Description

Octadecylmethylsiloxane, Dimethylsiloxane Copolymer is a specialized organosilicon polymer engineered to provide unique surface-modifying and release properties. This copolymer is valued for its ability to impart hydrophobicity, lubricity, and excellent thermal stability to formulations and substrates. It is an essential additive for manufacturers in the personal care, coatings, plastics, and textile industries seeking to enhance product performance and processing efficiency.

Application

• Personal Care & Cosmetics: Acts as an efficient emollient and conditioning agent in skincare, haircare, and color cosmetics, providing a smooth, non-greasy feel and improved spreadability.
• Industrial & Textile Coatings: Used as a water-repellent additive and surface modifier to create hydrophobic, anti-stick, and anti-fouling coatings for fabrics, paper, and metals.
• Plastics & Rubber Processing: Functions as an internal and external lubricant and mold release agent, improving flow properties and facilitating demolding in polymer processing.
• Adhesives & Sealants: Imparts water resistance and modifies surface energy to enhance adhesion or provide controlled release properties in pressure-sensitive and silicone-based systems.
• Polishes & Waxes: Serves as a key ingredient to enhance gloss, durability, and water-beading effects in automotive and furniture polish formulations.
• Pharmaceutical & Topical Formulations: Employed as a skin-protectant and occlusive agent in ointments and creams, helping to form a protective barrier and control moisture loss.

Basic Information

Product Name	Octadecylmethylsiloxane, Dimethylsiloxane Copolymer
CAS No.	67762-83-8
Molecular Formula	(C2H6OSi)m(C19H42OSi)n
Molecular Weight	Varies by copolymer ratio
Synonyms	Stearyl Methyl Siloxane-Dimethyl Siloxane Copolymer; Poly(dimethylsiloxane-co-methyloctadecylsiloxane); Cetyl Dimethicone; Stearyl Dimethicone; Octadecyl Methyl Siloxane Homopolymer; Methyloctadecylsiloxane-dimethylsiloxane Copolymer; PDMS-co-PMOS; Silicone Copolymer with C18 Alkyl Chain
EINECS	Contact for details

Quality Control

Our Octadecylmethylsiloxane, Dimethylsiloxane Copolymer is manufactured under a strict quality management system. Each batch undergoes rigorous analytical testing to ensure consistent performance, including verification of viscosity, specific gravity, refractive index, and functional group composition. Certificates of Analysis (COA) documenting these parameters are available upon request to support your quality assurance and regulatory compliance needs.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area at room temperature (15-25°C). Keep away from strong oxidizing agents and heat sources to maintain product integrity.

Specification

Item	Specification
Appearance	Clear, colorless to pale yellow viscous liquid
Identification (IR)	Conforms to structure
Viscosity (25°C)	Specification available upon request
Specific Gravity (25°C)	0.86 - 0.98
Refractive Index (25°C)	1.400 - 1.460
Assay (Siloxane Content)	≥ 98.0%
Water Content	≤ 0.5%

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.